The Lincoln Electric Company

Lincoln Global, Inc.

Dale L Bilczo

Larry L Church

Lawrence A Boehnlein

Craig L Diekmann

Kenneth Anthony Golonka

Larry B Solski

John Ernest Carroll

Michael J Kurchak

John Arthur Overman

An apparatus for an electric arc welder comprising a first electromagnetic device including a first core assembly, wherein the first core assembly has a first stack of laminations which are press-fitted or snapped together into interlocking engagement with a complementary second stack of laminations so as to form two flux paths through the first core assembly, each of which passes through a center portion of the first core assembly; a second electromagnetic device, such as a transformer, including a second core assembly, wherein the second core assembly has a first stack of laminations which are press-fitted or snapped together into interlocking engagement with a complementary second stack of laminations so as to form two flux paths through the second core assembly, each of which passes through a center portion of the second core assembly; and wherein the two core assemblies of the electromagnetic devices are press-fitted or snapped together into interlocking engagement with each other.

Snap-together choke and transformer assembly for an electric arc welder

There is provided an improvement in an inverter power supply of the type including an output transformer of the type having a high permeability magnetic core, input winding means for applying input current pulses to the core; a first output winding wound on the core; and a second output winding wound on the core. The power supply further includes first and second output terminals and output circuit means for connecting the individual output windings to the terminals in a fashion that opposite polarity output current pulses induced in the output windings by the input current pulses are applied across the terminals in a preselected first polarity. The improvement in this power supply comprises forming the output transformer with the two output windings having essentially the same number of turns and being wound in a selected direction so that current flow caused by freewheeling from an output inductor will flow simultaneously through the two output windings in a direction to cause opposite polarity magnetizing flux in the transformer core and providing means for mounting the two output windings of the transformer adjacent to each other on the core in a tight overlapping relationship with a coefficient of coupling greater than 0.950 and preferably greater than 0.980. The best results are obtained with the coefficient greater than 0.990.

Inverter output circuit

A control circuit is provided for the output of a high frequency inverter of the type having an output transformer with a core, primary windings and a secondary winding with two sections for creating a first secondary current pulse of electrical current in one section when the primary windings magnetizes the core and a second secondary current pulse in the other of the secondary sections when the primary windings remagnetizes the core. By alternating switch means for passing current through the primaries to magnetize and remagnetize the core at a preselected rate the output current pulses are provided by the two sections of secondary windings. The control circuit of the present invention involves a modification of the output transformer secondary stage. A first auxiliary winding is connected to one of the secondary sections to create an auxiliary current pulse as the core of the transformer is magnetized. A means is then employed for limiting this auxiliary current pulse and for adding the limited auxiliary current pulse to the first secondary pulse created by the secondary section to which the auxiliary winding is connected. In a like manner, a second auxiliary winding is connected to the other of the secondary sections to create a second auxiliary current pulse as the core is remagnetized. Means are provided for limiting the second auxiliary current pulse and for adding the second auxiliary current pulse to the second secondary current pulse from the secondary winding. Addition of limited current pulses to secondary current pulses created by the inverter provides a maximum output voltage which is higher than the maximum output voltage normally available while conserving primary current under higher output current conditions.

Output control circuit for inverter

A three phase electric arc welding power supply using SCR rectifiers for output control which has improved output characteristics, fault protection and current and voltage controls. The main power transformer includes two secondaries connected in a double wye with the neutral points supplying power to one of the output terminals a pair of independent inductances are in series, one with each set of secondaries. Increased phaseback of the SCR's may be effected without the use of additional inductance in the output circuit. The fault protection circuit has a time-current trip curve closely approximating the time-current overload curve of the SCR's whereby the minimum size SCR's for a given maximum current output is obtained. The control circuit is fast responding and gives either: constant voltage output; or variable voltage, constant current output with both line voltage compensation and with increase of current when the arc is shorted and the arc voltage drops below a predetermined amount. Improved firing circuits for the main and pilot SCR's are provided.

Growing community of inventors

Rocky River, OH, United States of America

Dale L Bilczo